Print Email Facebook Twitter Improving jack-up capabilities Title Improving jack-up capabilities Author Dimitriou, A. Contributor Metrikine, A. (mentor) Faculty Mechanical, Maritime and Materials Engineering Department Offshore and Dredging Programme Bottom Founded Structures Date 2014-08-26 Abstract So far jack-ups have successfully operated in depths of 80 to 100 m and some are capable of operating in water depths of up to 150 m. In order to circumvent the depth limitation, it was suggested by Heerema Marine Contractors (HMC) that a base could be designed with the ability to support a jack-up rig, thereby increasing its operational depth capability. Such a support structure for jack-ups (named SSfJ) that can possibly be mobilized and demobilized by an HMC vessel would allow HMC to offer its services to another part of the Oil and Gas industry, the Drilling and Workover sector. A first investigation into the feasibility of this idea is carried out in this thesis. The focus of the thesis is placed on determining whether a 3-legged North Sea drilling jack-up can potentially survive on a SSfJ and on the calculation of the structural characteristics of the SSfJ that are required for enabling a jack-up to do so. The first step in this research was to verify if there is a commercial driver for the SSfJ. Therefore a market research took place which focused on the North Sea offshore drilling industry and showed that there is a need for high spec and deep water jack-ups and a great need for reduction in drilling costs. The driver was therefore clear, namely that there is a need to design a SSfJ that will enable jack-ups to operate in deeper water without much increase in costs. Then, based on market information it was decided to consider a SSfJ that would add 30m of water depth capability to the GustoMSC CJ 70 jack-up type. The main (technical) part of the thesis focused on identifying how the jack-up integrity will be influenced when it is placed on the SSfJ and what structural characteristics the SSfJ should have in order to enable a jack-up to survive on it through the harshest North Sea environmental conditions. The influence of the use of the SSfJ was assessed via reasonable assumptions that were then verified with analysis in the software SACS. The required structural characteristics of the SSfJ were identified as the SSfJ stiffness and rotational fixity at the SSfJ – jack-up interface. Recommended values for these characteristics were identified via an iterative procedure that includes a simplified dynamic analysis method that uses a Dynamic Amplification Factor. The results were then verified with a more accurate method that employs the time domain simulations in SACS. The outcome of the research is that the jack-up integrity is not influenced negatively by the use of SSfJ and that if the SSfJ has the recommended structural characteristics then the jack-up can survive the harshest environmental conditions in the North Sea. Subject jack-upNorth Sea To reference this document use: http://resolver.tudelft.nl/uuid:4cae9d4c-02f1-497c-b676-e3c00067baf9 Embargo date 2014-09-01 Part of collection Student theses Document type master thesis Rights (c) 2014 Dimitriou, A. Files PDF Thesis_Main_Report-Arista ... itriou.pdf 4.77 MB Close viewer /islandora/object/uuid:4cae9d4c-02f1-497c-b676-e3c00067baf9/datastream/OBJ/view